Rocket primer



L. A. SKINNER Feb, 22, 1'49.

ROCKET PRIMER Filed'April 6, 1944 LrEEliE A 5k inner Patented Feb. 22, 1949 UNITED STATES eaTeNT OFFICE.

(Granted under the act of March 3, 1883, as

amended April 30, 1928; .370 OJ G; 757) The invention described herein may be manufactured and used by or for the Government for governmental purposes, without the payment to me of. any royalty thereon.

the ring and disc,contacts. 'The plate :.I [,withs squib Zil held by its soldered lead wires, is then: screwed into cup l0, and the latter loadeduwithw black gunpowder I1. For this purpose the bottom I This invention relates to rocket projectiles and 5 of cup H] has a largeloading, hole I8 whichlis; more particularly to an electrical igniter carried closed after the loading operation by a disc-l9 by the rocketand adapted to ignite its propellant preferably made of cloth and conveniently held charge upon firing or launching. It is an object in place by shellac. The border surrounding load-i of this invention to provide an improved elecing hole I8 is coated with shellac as is the inside trical igniter which is adapted to be inserted in 10 border of cloth disc 19; ,after the disczis posi-- the rear end of the rocket projectile and which is tioned in place, a final coat of shellacis :applied 5 provided with electrical contact means which are over the disc. contacted by electrical switches provided on the The edge of plate II is tapered in substantial... rocket gun or launcher. The rocket is launched conformity to the taper of the rocket nozzle :9, by closing the electrical circuit, which includes and the igniter assembly, or rather the plate II,: the said contacts provided in the igniter, to a is press fitted in the nozzle, with the cup III exsource of current. For the attainment of this tending into the expansion nozzle 8 of the rocket and such other objects of invention as may appear projectile I. A portion 'of the projecting or or be pointed out herein I have shown one emlaunching mechanism is shown in Fig. 1 and bears bodiment of my invention in the accompanying 20 the reference character 30. Launching tube 3|] is drawing, wherein: provided with a pair of switch contactsv pivoted Fig. 1 shows the rear 'portion of a rocket proat 3I, one of the switches 33 being contactable jectil 'with its rear nozzle mouth in section to with the outer ring I3 and the otheryof the reveal the improvedigniter; switches 34 being contactable withthe inner disc Fig. 2 is a longitudinal section through the im- I4.' The pair of switches are turned to out-of-. proved igniter; contact position, shown in dot-and-dash lines in Fig. 3 shows the outer contact ring and Fig. 1, preparatory to loading the rocket .I -in Fig. 4shows the inner contact disc. launching tube 30. After the rocket has :been* The igniter comprises a cup I 0 preferably placed in the breech end of the launcher, the fabricated of plastic but which may be made of pair of electrical switches 33 and 34 are turned to other material. Plastic cup I 0 is internally contact the respective contacts I3and I4 of the threaded at its mouth to receive a circular closure igniter, this contact position, of the switches being; plate II provided with an annular rim I2 which is shown in 'solid lines in Fig. 1. The electrical externally threaded for screwing into the cup. switch mechanism of the launcher is implemented Instead of the threads, other joining means may with a tensile spring 32 arranged to either spring be used, such as a pressed fit between the mouth press the switches into contact with the ring and of cup I0 and rim I 2 of closure plate I I. Plate I I, disc surfaces of the igniter, or to hold the switches which likewise is preferably made of plastic, has in their out-of-contact position. inserted in its outer face an outer contact ring It should be observed that, by reason of the I3 and an inner centrally located contact disc I4. 40 center contact disc I land outer annular contact Contact ring I3 and contact disc I4, which are ring l3, the improved igniter may be placed in fabricated of brass or other suitable conducting the launching tube without regard to angular cometal, are preferably inserted in and made part ordination between the rocket and the launcher. of the plastic plate II during the molding opera- With the switches 33 and 34 in contact with the tion. Two holes are then drilled through the igniter, the rocket projectile is fired or launched closure plate II; one drill hole I5, inclined to the by closing the circuit, which includes the squib longitudinal axis of igniter cup I 0, passes through 20, contact surfaces I3 and I4 and switch contacts the outer contact rin I 3, while the other drill 33 and 34, to a source of urr nt t h w hole I6 parallel to the longitudinal axis of the The rocket propellant with which the combuscup, passes through inner contact disc I4. The tion chamber of the rocket is charged is a doubletwo lead wires of an electrical fired squib or base powder requiringasustained pressure to enprimer 20 are then inserted in the two holes, squib sure satisfactory ignition. The improved igniter, W 25 in ring 0 8 5 and q i Wire 25 in disc by reason of the action of the black powder (I1, hole I6, and soldered in place; the end of the Fig. 2) with which it is charged, serves the added wires are then cut off flush with the surfaces of function of building up within the combustion chamber an initial pressure suflicient for the initial ignition and functioning of the propellant and to insure proper continued burning of the propellant.

I claim:

1. An electrical igniter adapted to be inserted in the nozzle opening of a rocket projectile and adapted to establish electrical contact with the the cup to close the said hole, an outer metal ring.

and an inner metal disc moulded in the said plastic plate with their exposed surfaces flush with the outer face of the plastic plate to furnish a pair of electrical contacts, the said plastic plate having a pair of drilled holes, one drill hole passing through the said outer ring and the other drill hole passing through the said inner disc, an electrically-fired primer positioned within the said plastic cup with its two lead wires soldered in the two said drilled holes, the edge of the said plastic plate being beveled to the taper of the said rocket nozzle and adapted to be press fitted in the nozzle, the said cup being received within the expansion nozzle of the rocket projectile with the said outer ring and inner disc positioned at the said rocket nozzle to be contacted by the said pair of electrical switches of the launcher irrespective of the angular position of either the electrical igniter or the rocket projectile.

2. An electrical igniter adapted to be inserted in the nozzle opening of a rocket projectile and adapted to establish electrical contact with the pair of electrical switches provided in the rocket launcher, comprising, in combination, a cup pro,- vided with internal threads at its mouth and with a centrally located hole in its bottom, a circular plate provided with an annular fiange externally threaded for screwing into the said threaded mouth of the cup, a cloth disc somewhat larger than the said cup hole and adapted to be shellacadhered to the outside of the cup to close the said hole, an outer metal ring and an inner metal disc held in the said plate with their exposed surfaces flush with the outer face of the plate to furnish a pair of electrical contacts, the said plate having a pair of drilled holes, one drill hole passing through the said outer rin and the other drill hole passing through the said inner disc, an electrically-fired primer positioned within; the said cup with its two'lead wires soldered in the two said drilled holes, the edge of the said plate being beveled to the taper of the said rocket nozzle and adapted to be press fitted in the nozzle, the said cup being received within the expansion nozzle of the rocket projectile with the said outer ring and inner disc positioned at the said rocket nozzle to be contacted by the said pair of electrical switches of the launcher irrespective of the angular position of either the electrical igniter or the rocket projectile.

3. An igniter comprising a plate of electrical insulating material adapted to fit within and to close the nozzle opening of a rocket projectile, a contact ring and a contact disc carried by said plate on the side thereof which faces outwardly of the rocket when the plate is fitted within the nozzle opening of the rocket projectile, said disc bein positioned within said ring and spaced therefrom, whereby two insu ated electricalcontacts are provided by said ring and disc, a con tainer for explosive carried by the plate on the side thereof opposite the side which carries the said ring and disc;.an electric squib in said container, one lead of, said squib passing through said plate and connecting with said ring and, the other lead of said squib passing through said plate and connecting with said disc; and a non-deto nating explosive in said container about said squib.

LESLIE A. SKINNER.

REFERENCES CITED The following references are of record in the.

file of this patent: 

